package com.zjmzxfzhl.common.util;

import java.net.InetAddress;
import java.net.UnknownHostException;

import javax.servlet.http.HttpServletRequest;

import com.zjmzxfzhl.common.Constants;

/**
 * @author 庄金明
 * @date 2020年3月23日
 */
public class IpUtils {
	private static final String UNKNOWN = "unknown";
	private static final String LOCAL_IP6 = "0:0:0:0:0:0:0:1";
	private static final String LOCAL_IP4 = "127.0.0.1";
	/**
	 * ***.***.***.***".length() = 15
	 */
	private static final int IP_MAX_LENGTH = 15;

	public static String getIpAddr(HttpServletRequest request) {
		String ipAddress = request.getHeader("x-forwarded-for");
		if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getHeader("Proxy-Client-IP");
		}
		if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getHeader("WL-Proxy-Client-IP");
		}
		if (ipAddress == null || ipAddress.length() == 0 || UNKNOWN.equalsIgnoreCase(ipAddress)) {
			ipAddress = request.getRemoteAddr();
			if (LOCAL_IP4.equals(ipAddress) || LOCAL_IP6.equals(ipAddress)) {
				// 根据网卡取本机配置的IP
				InetAddress inet = null;
				try {
					inet = InetAddress.getLocalHost();
				} catch (UnknownHostException e) {
					e.printStackTrace();
				}
				ipAddress = inet.getHostAddress();
			}
		}
		// 对于通过多个代理的情况，第一个IP为客户端真实IP,多个IP按照','分割
		// "***.***.***.***".length() = 15
		if (ipAddress != null && ipAddress.length() > IP_MAX_LENGTH) {
			if (ipAddress.indexOf(Constants.COMMA) > 0) {
				ipAddress = ipAddress.substring(0, ipAddress.indexOf(","));
			}
		}
		return ipAddress;
	}

}
